Noninvasive Evaluation of Coronary Artery Disease:

Anatomical, Functional, Clinical

May 5, 2018

Mark Hansen MD FRCPC Cardiologist, Schulich Heart Centre Assistant Professor, Department of Medicine University of Toronto

21st Annual Contemporary Therapeutic Issues in Cardiovascular Disease

No Conflict or Disclosure

LEARNING OBJECTIVES

To develop a greater understanding of the application of cardiac imaging modalities in the detection and management of coronary artery disease:

stress echocardiography myocardial perfusion imaging coronary CT angiography

Coronary Artery Disease

Libby P NEJM 2013;368:2004-2013

Hansson G NEJM 2005;352:1685-1695

Libby P, Theroux P, Circulation 2005;111:23481-3488

When seeking an answer, begin with the right question

Detection vs. Management?

Anatomy vs. Function?

Diagnosis vs. Prognosis?

Case

49 year old male Phys. Ed. teacher Diminished exercise capacity ?aging Positive family history of premature CAD BP 148/88 Glucose 5.4 Cholesterol 6.88, TG 4.92, HDL 1.28 GXT: 12min Bruce, 12.8METs, mild dyspnea, peak BP 210/73, 2mm horizontal ST depressions

Case

49 year old male Phys. Ed. teacher Diminished exercise capacity ?aging Positive family history of premature CAD BP 148/88 Glucose 5.4 Cholesterol 6.88, TG 4.92, HDL 1.28 GXT: 12min Bruce, 12.8METs, mild dyspnea, peak BP 210/73, 2mm horizontal ST depressions

What Now?

What Now?

Reassurance? Medical therapy? Stress echocardiography? Myocardial perfusion imaging? CT coronary angiography? Invasive coronary angiography?

The Ischemic Cascade

The Ischemic Cascade

The Ischemic Cascade

The Ischemic Cascade

Will this information:

change health behaviour? change management?

Is this investigation:

cost effective? worth the risk?

Case - cont.

Referred for stress echocardiography

STRESS IMAGING

StressRest

Exercise

Pharmacological

STRESS ECHO

StressRest

Exercise

Dobutamine

STRESS ECHO

DisadvantagesAdvantagesCheap No radiation Specific

Operator-dependent Not very sensitive e.g. circumflex ischemia

Special ConsiderationsExtensive literature on pre-op evaluation (dobutamine) Poor images = poor accuracy Inadequate stress = nondiagnostic test Challenging when baseline wall motion abnormality

STRESS ECHO

Ideal LabIdeal PatientRule-in scenario Interpretable ECG Good image quality Capable of reaching max HR Normal baseline LV function (Serial follow-up)

Direct MD supervision Excellent equipment Excellent sonographer

Case - cont.

Stress echocardiography: 12min Bruce, 12.8METs, mild dyspnea, 2mm horizontal ST depressions, normal left ventricular systolic function at rest and stress

What Now?

Case - cont.

Referred for myocardial perfusion imaging

MYOCARDIAL PERFUSION IMAGING

StressRest

ExercisePersantineAdenosine

MYOCARDIAL PERFUSION IMAGING

DisadvantagesAdvantagesSensitive Quantitative Less operator dependent

Expensive Radiation Less specific (Breast, diaphragm attenuation)

Special ConsiderationsVery extensive literature on prognosis Applicable to known CAD LBBB (pharmacological) Inadequate stress = nondiagnostic test

Ideal LabIdeal PatientRule-out scenario Intermediate body habitus (Not serial follow-up)

Excellent equipment Excellent analysis Case correlation

MYOCARDIAL PERFUSION IMAGING

Einstein A et al. Circulation 2007;116:1290-1305

Case - cont.

Exercise myocardial perfusion scan: 12min Bruce, 12.8METs, mild dyspnea, 2mm horizontal ST depressions, normal myocardial scintigraphy, left ventricular volumes, and scintigraphy at rest and stress

What Now?

Boiten H et al. J Nuc Card 2016

Case - cont.

Referred for CT coronary angiography

CT CORONARY ANGIOGRAPHY

CT CORONARY ANGIOGRAPHY

DisadvantagesAdvantagesExcellent anatomical information Sensitive & specific Quantitative Less operator dependent

Relatively expensive Radiation Contrast Does not provide functional information

Heart rate-dependent Beta-blocker, NTG pre-treatment

Special Considerations

Ideal LabIdeal PatientBradycardia Rule-out scenario Not previous PCI Not extensive Ca++ (Not serial follow-up)

Excellent equipment Excellent analysis Case correlation

CT CORONARY ANGIOGRAPHY

RANDOMIZED TRIALS IN CARDIOVASCULAR IMAGING

CHALLENGES: ?Study population Core lab vs. community / real life? Indirect association between imaging strategy and outcomes. ?What endpoint

Accuracy? Clinical outcomes? Patient-centred outcomes? Cost-effectiveness?

NEJM 2015;372(14)

NEJM 2015;372(14)

PROMISE STUDY

Lancet 2015;385:9985:2383-2391

J Am Coll Cardiol Img 2011;4:740 –51

J A C C : C A R D I O V A S C U L A R I M A G I N G V O L . 4 , N O . 7 , 2 0 1 1

J A C C : C A R D I O V A S C U L A R I M A G I N G V O L . 4 , N O . 7 , 2 0 1 1

Case - cont.

Agatston (Coronary Artery Calcium) score: 0 “No significant coronary arterial calcification in all three vessels. Minimal noncalcified plaque at the proximal D1 causing less than 30% narrowing of the lumen”

Case - cont.

Agatston (Coronary Artery Calcium) score: 0 “No significant coronary arterial calcification in all three vessels. Minimal noncalcified plaque at the proximal D1 causing less than 30% narrowing of the lumen”

What Now?

What Now?

Reassurance? Medical therapy? Repeat stress testing? Invasive coronary angiography?

What Now?

Reassurance? Medical therapy? Repeat stress testing? Invasive coronary angiography?

Advised to take ASA, statin, ACE-inhibitor… patient declined

6 weeks later…

Conclusions

GXT, Stress Echo, Myocardial Perfusion Imaging and CT coronary angiography are all reasonable initial diagnostic strategies in patients with suspected coronary artery disease. Choice should be informed by patient factors and local resources. Coronary risk can be estimated, but events are difficult to predict. Integration of all clinical data is necessary in formulating a treatment plan.

SUMMARY